The present invention is directed to devices for automatically controlling fluid flow. It has particular application to household uses, such as the control of water flow in a kitchen or bathroom sink or in a shower head, but it has related non-domestic uses.
Previously proposed automatic flow-control devices, such as the automatic faucet of U.S. Pat. No. 4,402,095 to Pepper, have certain disadvantages in the ordinary household environment. For example, most existing automatic faucets are no easier to install than conventional manual faucets are. This is a problem because most automatic faucets are to be installed in existing houses, not in new construction. Therefore, the homeowner is put to the added expense of hiring a plumber to replace the existing manual faucet with an automatic one unless he has the skill and the inclination to remove the existing faucet and install the new one.
Another problem is that currently available automatic faucets require power sources. In the context of existing construction, this means that the homeowner must employ not only a plumber but also an electrician if the power source is to be the ordinary household electrical circuit. The problem is aggravated in many cases because an electrical outlet is not located conveniently close to the faucet.
In the alternative, the power source could be carried on board the automatic faucet itself; for example, the faucet could include a battery pack. However, operation of the electrically operated valve can cause a significant power drain, and this can result in the need to replace batteries unacceptably often.
It is accordingly an object of one aspect of the present invention to simplify automatic-faucet installation. It is an object of another aspect of the present invention to reduce automatic-faucet power requirements.